The present invention relates to the battery arrangement for a motor vehicle with a plurality of battery modules. The present invention also relates to a motor vehicle. Finally the present invention relates to a method for testing an electrical connection between at least two battery modules of a battery arrangement for a motor vehicle.
In motor vehicles battery arrangements are used for the electrical supply of operating components of the motor vehicle. In particular in electric vehicles traction batteries are used which include multiple battery modules connected in series in order to achieve a correspondingly high overall voltage so that the required power can be transmitted. These battery modules can include a plurality of battery cells or individual cells which can for example be made of lithium ion cells or cells with other cells for example a nickel metal hybrid accumulator (NiMH). Usually the battery cells are monitored by a higher level monitoring device or a battery management system. Hereby a measuring line or sensor line is guided from each of the battery cells into the battery management. These measuring lines also enabling recognizing during the assembly of such a battery arrangement the electrical voltage that has already been achieved in the overall system. By taking targeted influence on the mounting order it is also possible to achieve a dangerous voltage for example a DC voltage over 60 V as late as possible.
The approach for modularization of such a battery arrangement is also known. Hereby it is sought to keep the analysis of the cell voltages on the modular level. The individual battery modules communicate their measuring values then via the corresponding bus system (e.g. CAN-bus) to a higher level battery management system. Hereby the individual battery module are each coupled with a corresponding control unit. This control unit knows the electrical connection and the electrical voltage provided by the battery module and provides this information to the higher level monitoring device for the higher level battery management system. No information regarding the connection of the modules to each other is available to the respective control units of the battery modules. Similarly the information regarding the electrical voltage provided by the battery arrangement are available in the higher level battery management system only after assembly of the battery arrangement. As a consequence the electrical voltage, which is present at the battery arrangement cannot be traced during the assembly of the battery arrangement. This also does not allow determining a possible risk during assembly of the battery arrangement.
DE 198 10 746 B4 describes a circuit board with a circuit for monitoring a multi cellular accumulator battery, with which the electrical voltage and the temperature of the individual cells in the battery can be detected. The circuit board also has inputs and outputs which are connected to a data bus which connects the battery with further batteries and a central battery management system.
Further methods is known from DE 10 2008 058 924 B4 for identifying and quality documentation of accumulators for industrial tools. Hereby the data of the accumulator such as its serial number are stored in a corresponding component. These data can be modulated onto to the current line which is assigned to the accumulator.
DE 10 2010 016 175 A1 describes a device for monitoring and controlling a battery wherein each battery cell in the battery is assigned a battery monitoring module. The device also includes a system controller, which is configured to monitor the battery modules, to retrieve data from the battery modules and to execute commands for controlling the charge compensation.
A battery with multiple individual cells, which are connected in series and which are connected to each other via a common current line for charging the individual cells is described in DE 195 45 833 B4. Hereby each individual cell of the battery is assigned an individual cells module, which has the capability to receive and execute individual charge signals. The individual charge signals are outputted by a central unit via the current line, which can be configured as modulated field bus.
In addition DE 103 37 243 A1 discloses a battery testing module for accumulator batteries in which a plurality of battery cells are connected in series in a battery housing. With the battery testing module information relating to the properties of the battery can be provided. The battery testing module is configured to receive and transmit data such as the serial number of the battery. These data can also be provided to the positive and negative connections of the battery.
Finally U.S. Pat. No. 6,184,656 B1 describes a battery arrangement with a plurality of battery modules, which can each include multiple battery cells. Hereby each battery module is assigned a control unit. Each of the control units is configured to send data and to receive data from other control units via the electrical connecting lines with which the individual battery modules are electrically connected. With the control units data can also be sent to a higher level monitoring device.